﻿// <copyright file="App.xaml.cs" company="Microsoft Corporation">
// Copyright (c) 2009 Microsoft Corporation All Rights Reserved
// </copyright>
// <author>Michael S. Scherotter</author>
// <email>mischero@microsoft.com</email>
// <date>2010-08-20</date>
// <summary>App code behind</summary>

namespace WindowsPhoneListApplication
{
    using System.Windows;
    using System.Windows.Navigation;
    using Microsoft.Phone.Controls;
    using Microsoft.Phone.Shell;

    /// <summary>
    /// Application code behind
    /// </summary>
    public partial class App : Application
    {
        #region Fields
        /// <summary>
        /// Static view model
        /// </summary>
        private static MainViewModel viewModel = null;

        /// <summary>
        /// Avoid double-initialization
        /// </summary>
        private bool phoneApplicationInitialized = false;
        #endregion

        #region Constructors
        /// <summary>
        /// Initializes a new instance of the App class
        /// </summary>
        public App()
        {
            // Global handler for uncaught exceptions. 
            // Note that exceptions thrown by ApplicationBarItem.Click will not get caught here.
            UnhandledException += this.Application_UnhandledException;

            // Standard Silverlight initialization
            InitializeComponent();

            // Phone-specific initialization
            this.InitializePhoneApplication();
        }
        #endregion

        #region Properties
        /// <summary>
        /// Gets the static view mode
        /// </summary>
        public static MainViewModel ViewModel
        {
            get
            {
                // Delay creation of the view model until necessary
                if (viewModel == null)
                {
                    viewModel = new MainViewModel();
                }

                return viewModel;
            }
        }

        /// <summary>
        /// Gets easy access to the root frame
        /// </summary>
        public PhoneApplicationFrame RootFrame { get; private set; }

        #endregion

        /// <summary>
        /// Code to execute when the application is launching (eg, from Start)
        /// This code will not execute when the application is reactivated
        /// </summary>
        /// <param name="sender">the application</param>
        /// <param name="e">the launching event arguments</param>
        private void Application_Launching(object sender, LaunchingEventArgs e)
        {
        }

        /// <summary>
        /// Code to execute when the application is activated (brought to foreground)
        /// This code will not execute when the application is first launched
        /// </summary>
        /// <param name="sender">the applicaitno</param>
        /// <param name="e">the activated event arguments</param>
        private void Application_Activated(object sender, ActivatedEventArgs e)
        {
        }

        /// <summary>
        /// Code to execute when the application is deactivated (sent to background)
        /// This code will not execute when the application is closing
        /// </summary>
        /// <param name="sender">the application</param>
        /// <param name="e">the deactivated event arguments</param>
        private void Application_Deactivated(object sender, DeactivatedEventArgs e)
        {
        }

        /// <summary>
        /// Code to execute when the application is closing (eg, user hit Back)
        /// This code will not execute when the application is deactivated
        /// </summary>
        /// <param name="sender">the application</param>
        /// <param name="e">the closing event arguments</param>
        private void Application_Closing(object sender, ClosingEventArgs e)
        {
        }

        /// <summary>
        /// Code to execute if a navigation fails
        /// </summary>
        /// <param name="sender">the root frame</param>
        /// <param name="e">the navigation failed event arguments</param>
        private void RootFrame_NavigationFailed(object sender, NavigationFailedEventArgs e)
        {
            if (System.Diagnostics.Debugger.IsAttached)
            {
                // A navigation has failed; break into the debugger
                System.Diagnostics.Debugger.Break();
            }
        }

        /// <summary>
        /// Code to execute on Unhandled Exceptions
        /// </summary>
        /// <param name="sender">the application</param>
        /// <param name="e">the application unhandled exception event arguments</param>
        private void Application_UnhandledException(object sender, ApplicationUnhandledExceptionEventArgs e)
        {
            if (System.Diagnostics.Debugger.IsAttached)
            {
                // An unhandled exception has occurred; break into the debugger
                System.Diagnostics.Debugger.Break();
            }
        }

        #region Phone application initialization

        /// <summary>
        /// Do not add any additional code to this method
        /// </summary>
        private void InitializePhoneApplication()
        {
            if (this.phoneApplicationInitialized)
            {
                return;
            }

            // Create the frame but don't set it as RootVisual yet; this allows the splash
            // screen to remain active until the application is ready to render.
            this.RootFrame = new PhoneApplicationFrame();
            this.RootFrame.Navigated += this.CompleteInitializePhoneApplication;

            // Handle navigation failures
            this.RootFrame.NavigationFailed += this.RootFrame_NavigationFailed;

            // Ensure we don't initialize again
            this.phoneApplicationInitialized = true;
        }

        /// <summary>
        /// Do not add any additional code to this method
        /// </summary>
        /// <param name="sender">the PhoneApplicationFrame</param>
        /// <param name="e">the Navigation event arguments</param>
        private void CompleteInitializePhoneApplication(object sender, NavigationEventArgs e)
        {
            // Set the root visual to allow the application to render
            if (RootVisual != this.RootFrame)
            {
                RootVisual = this.RootFrame;
            }

            // Remove this handler since it is no longer needed
            this.RootFrame.Navigated -= this.CompleteInitializePhoneApplication;
        }

        #endregion
    }
}
